In recent years, a vibrating device which makes a user feel a “push” of a key by transmitting a vibration when the user touches the key on a touch panel keyboard has been proposed.
For example, Patent Document 1 discloses an electronic device which includes a touch panel sensor which detects a user's touch on a key, a piezoelectric bimorph element (piezoelectric body) which is made of piezoelectric ceramics, and vibration control means (drive circuit) which applies an alternating-current drive signal to the piezoelectric bimorph element. Both ends of the piezoelectric bimorph element are held by support members, and a vibrated body (diaphragm) is provided at a center of the piezoelectric bimorph element.
The electronic device of Patent Document 1 transmits a vibration to a user via the connected vibrated body (diaphragm) by applying an alternating-current drive signal to the piezoelectric bimorph element to vibrate. Thus, the electronic device of Patent Document 1 gives a tactile feedback to the user and makes the user feel a “push” of a key.
Patent Document 1: Japanese Patent Application Laid-Open No. 2005-303937,
However, the drive circuit that applies a drive signal frequently causes electromagnetic noise in the electronic device in Patent Document 1. Further, the electronic device of Patent Document 1 includes a sensor which detects a user's touch on a key.
Hence, the sensor is likely to cause an error operation due to the electromagnetic noise caused by the drive circuit in the electronic device of Patent Document 1.